How do the roles of Das Ganu and Gajanan Maharaj compare in helping Ratanji achieve his desire for a son?

Based on the provided sections of Chapter 14, it is not possible to compare the roles of Das Ganu and Gajanan Maharaj because Gajanan Maharaj is not mentioned at all. The text exclusively details the role of Das Ganu. Ratanji, a wealthy merchant distressed by his lack of a son, confided in Das Ganu. As recounted in Chapter 14, Das Ganu played the crucial role of a guide, directing the merchant to seek help from a higher power. He specifically told Ratanji to 'Go to Shirdi' and surrender to Sai Baba to have his wish fulfilled.